Detection of fungal and bacterial contamination of hazelnut and determination of aflatoxin B by HPLC method in Isfahan, Iran

Due to the fact that fungal species such as Aspergillus flavus and Aspergillus parasiticus produce carcinogenic and mutagenic aflatoxins and have the potential to produce fungal secondary metabolites, fungal contamination should be avoided. This study was conducted using the HPLC method and was aimed at examining the fungal contamination of Isfahan hazelnuts in order to identify the presence of Aflatoxins.

One hundred samples of hazelnuts were randomly collected from supermarkets in Isfahan. The samples were then cultured on Sabouraud dextrose agar (SDA) media and analyzed to determine fungal contaminations. The aflatoxin analysis was carried out using the HPLC method.

It was discovered that nine genera of fungi, namely Aspergillus, Penicillium , Rhizopus, Ulocladium, Alternaria, Drechselera, Trichothecium, Scopulariopsis, and Mucor were identified in 78% of the samples. Samples contaminated with Aspergillus flavus (22 samples) were studied to determine the presence of aflatoxin. The results showed that 16 (72.72%) of the samples were contaminated with AFB1, AFB2 and AFG2 and the mean concentrations were 0.926, 0.563 and 0.155ng/g, respectively.

Some parameters that affect mycotoxin production are temperature, food substrate, strain of the mold and other environmental factors. Due to the toxigenic quality of some of these fungi and their hazard to human health, it is crucial that fungal contamination and aflatoxin identification tests are carried out before certain products are made available to the mass market.